Automotive ignition contact point



Aug. 15, 1950 c. E. M CORMICK AUTOMOTIVE IGNITION CONTACT POINT Filed April 25, 1946 za 24 go INVENTOR: C/arence EA/IcCZr/fl d BY 4770 iewfr Patented Aug. 15, 1950 UNITED STATES PATENT OFFICE- 3 Claims.

This invention relates to automotive ignition systems and more particularly to the contact points and means of mounting the same.

The principal object of the invention is the provision of an improved contact point structure and means of mounting the same on a breaker arm of a distributor in an ignition system.

A further object of the invention is the provision of a method of aligning ignition contact points to insure fiat face-to-face contacts therebetween.

A still further object of the invention is the provision of an ignition system contact point mounting means incorporating a socket and a semi-spherical contact point mounted therein for movement therein to align a facet on said semispherical contact point with a fixed contact.

A still further object of the invention is the provision of a method of installing contact points employing at least one semi-spherical contact point mounted in a socket and normally held therein and capable of movement to align a facet of the semi-spherical contact point with a facet on a fixed contact point in the ignition system.

A still further object of the invention is the provision of a breaker arm for a distributor in an ignition system including a cup-shaped socket and means mounting a semi-spherical contact point therein for movement in said socket in aligning the said point with a secondary fixed point.

A still further object of the invention is the provision of a breaker arm for a distributor in an ignition system incorporating a cup-shaped socket having a half-round bod member comprising a contact point positioned therein by fusible material.

With the foregoing and other objects in View which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed can be made within the scope of what is claimed without departing from the spirit of the invention.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a top plan view of a portion of a distributor mechanism illustrating the improved contact point and means of mounting the same in the breaker arm of the distributor mechanism.

Figure 2 is a cross-section taken on line 22 of Figure 1.

Figure 3 is a cross section of a modified means of mounting a movable contact point.

Figure 4 is a cross section of a modified means of mounting a movable contact point.

Figure 5 is a cros section of a modified means of mounting a movable contact point.

By referring to the drawings and Figures 1 and 2 in particular it will be seen that the cam of a distributor mechanism is indicated by the numeral l0, an adjacently positioned bracket being indicated by the numeral l l. The bracket l I has an upturned end portion I2 carrying a stationary contact point 13. A pivot pin I4 is also positioned on the bracket H and an insulated bushing I5 is positioned thereabout. A breaker arm I 6 is positioned on the insulated bushing l5 of the pivot pin ill in a manner so that the outermost end of the breaker arm l6 lies adjacent the stationary contact point l3.

A curved leaf spring I l is afixed to the breaker arm l6 as by a rivet 18 which also mounts a fiber wiper [9 on the breaker arm I 6. The fiber wiper 19 engages the cam 10 to impart movement to the breaker arm I6 thus moving the outermost end of the breaker arm l6 alternately toward and away from the stationary contact point l3 when the cam I0 is rotated. The other end of the curved leaf spring I! is mounted on a section of insulation 20 by means of a bolt 21 and a nut 22. The section of insulation 20 is in turn mounted on a secondary upturned portion 23 Of the bracket I I as by means of a rivet 24. Openings 25 in the bracket ll provide for its mounting in the body portion of the distributor mechanism (not shown).

The outermost end of the breaker arm I S, which lies adjacent the stationary contact point I3, is provided with a cup-shaped socket 26, which, as is best shown in Figure 2 in enlarged detail, is provided with a tinned area 21 on the outer portion of the cup-shaped socket and with a fusible metal layer such as solder 28 on its inner or cupshaped surface. A half-round contact point 29 is mounted in the cup-shaped socket 26 by means of the fusible solder 28. The contact point 29 has a flat facet 30 which registers with the corresponding fiat facet of the stationary contact l3.

In installing the improved ignition contact point disclosed herein, the breaker arm I 8 carrying the movably mounted contact point 29 in the cup-shaped socket 26 thereof is positioned in the distributor mechanism in the usual manner. The fiat opposing registering surfaces of the contact point 29 and the stationary contact point I3 will not register perfectly except by chance.

Heat is then applied to the tinned area 21 of the cup-shaped socket 2B of the breaker arm iii to momentarily fuse the fusible solder 28 thereby permitting the half-round contact point 29 to partially revolve in the cup-shaped socket 26 and thereby bring its flat facet 38 into flat, perfect alignment with the corresponding flat facet of the stationary contact point it. When this occurs the solder 28 again hardens and the point is permanently set in perfect adjustment.

The advantage of this construction and method of alignment is seen in the fact that perfectly aligned contact points do not pit or burn and are therefore capable of giving uninterrupted, good service in an automative vehicle; for example, by providing uniform ignition through the points at all times. This is in contrast to the customary contact point construction wherein only an approximate registry between the contact points is ever attained, with the result that high spots cause limited areas of engagement and the electricity flowing through these quickly burns and pits the points, thereby further increasing the non-conductive area. By maintaining the contact points in perfect alignment, adequate area is provided for the flow of electric current, thereby eliminating the possibility of burning the contact points.

Modifications in the method of mounting the half-round or semi-spherical contact 29 will ocour to those skilled in the art and three such modifications are illustrated in Figures 3, 4 and of the drawings.

In Figure 3 of the drawings a half-round contact point 3|, having a flat facet 32, is provided with a threaded stud 33 which is positioned through an opening (it in a cup-shaped socket 35 of a breaker arm 36. A nut '51 is threadably engaged with the threaded stud 33 and it will be observed that the opening 34 is of a larger diameter than the diameter of the stud 33. When this construction is installed in a distributor mechanism, the nut 3i is loosened to permit the halfround or semi-spherical contact point 3! to align its fiat facet 3?. with the corresponding stationary contact (not shown) and the nut 31 is then tightened, thus securing the contact in position.

In Figure 4 of the drawings a semi-spherical contact point 38, having a fiat facet 39 thereon, is. mounted in a cup-shaped socket lll in the end of a breaker arm M by means of a clamping member 42 having an opening 43 therein of a diameter slightly smaller than the largest diameter of the semi-spherical contact point 38 so that the con tact point 33 is retained between the clamping member 42 and the socket All. A bolt 44 and a nut 45 hold the clamping member on the breaker arm 4 i. The operation is the same as that heretofore described in connection with the modification shown in Figure 3.

In Figure 5 of the drawings a further modification is shown in which a cup-like socket 46 is formed on the end of a breaker arm 41 and a semi-spherical contact point 48 having a flat facet 49 is positioned therein by means of fusible solder 50 and a mechanical retaining ring 5| having a flanged opening 52 formed herein of a diameter slightly less than the largest diameter of the semi-spherical contact point 48. The flanged retaining ring 5| is held on the breaker arm 4! by means of a rivet 53. In this modification, the semi-spherical contact point is installed and adjusted by means of the application of heat, as heretofore described in connection with Figures 1 and 2 of the drawings. The flanged retaining ring 5| serves to retain the contact point 48 in the event the fusible material should accidentally be fused during the operation of the distributor.

In actual practice, contact points of the construction illustrated in Figures 1 and 2 have been successfully operated over many thousands of miles and it has been determined that the actual operating temperatures of distributors are not great enough to fuse the solder, but the possibility of such fusion is anticipated in the construction disclosed in Figure 5 of the drawings and heretofore described.

It will be obvious to those skilled in the art that the precise embodiment of the contact point disclosed herein can be altered to locate the movably adjustable contact point as the fixed contact point in an automotive ignition system.

Having thus described my invention, what I claim is:

1. In an ignition system including a stationary contact point having a flat facet and a movable contact point, means mounting the said movable contact point including a socket, a semi-spherical contact point normally firmly mounted in said socket by a temporarily fusible metal, a fiat facet on said semi-spherical contact point for engaging the flat facet of the said stationary contact point, the said stationary contact point and semispherical contact point adapted to be aligned by temporarily fusing the said temporarily fusible metal to permit the semi-spherical contact point to partially rotate in the said socket to bring the flat facet thereof into fiat face to face engagement wih the flat facet of the stationary contact point.

2. In a distributor mechanism a breaker arm having a socket formed thereon and a semispherical contact point positioned therein, and fusible solder for normally holding the said semispherical contact point against rotation in the said socket and permitting rotation thereof when fused.

3. In a distributor mechanism including a breaker arm, a socket formed in said breaker arm, a semi-spherical contact point mounted in said socket by means of fusible metal, a retaining member having a flanged opening formed therein of a diameter less than the diameter of the semispherical contact and forming secondary means r retaining the said semi-spherical contact in the said socket, and means affixing the said retaining member to the said breaker arm.

CLARENCE E. McCORMICK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

